Manufacture of fiber board



Patented Apr. 12, 1927.

UNITED STATES PATENT-TOFFEE."

ROBERT W. HILTON, DECEASED, LATE OF CINCINNATI, OHIO; BY DANESI M.HILTON, EXECUTRIX, 0F CINCINNATI, OHIO, ASSIGNOB TO THE KEMPER-THOMASCOMPANY, OF NORWOOD, OHIO, A CORPORATION OF OHIO.

MANUFACTURE FIBER BOARD.

No Drawing.

The invention relates to improvements in the manufacture of fiber board,and particularly to a fiber board which is especially adapted for use inthe manufacture of printedsigns. I

The object of the inventlon 1s to produce a fiber board, suitable forthe manufacture.

of signs which will be as nearly as possible impervious to water, sothat the disintegrating effect of weathering, particularly of. re-

peated wettingand drying will be reduced to a minimum.

Application filed November 1, 1923. Serial No. 672,208.

soap of fatty acids such as oleic, stearic, and

palmitic acids, the same permitted to distimatelv associated with thefibers in the beater charge.

Then are added the salts of some metals which form insoluble soaps ofthe or auic A fiber board, made according to the proc- 4 such an oilphase and which are readily wetted by Water. i

Furthermore the printing surface of the treated board is smoother andfreer from irregularities, thereby allowing the ink printed upon ittolcover the surface more smoothly and to lie smoother than on 'ordi:

nary board. i

The essential step in this invention is to coat the fibers of a piece ofboard, with an .insoluble metal soap, thereby rotecting the fibers andmaking the boar waterproof, excellent to print, smooth aftercalendering, and upon which the rinted surface will be smooth and freefiiom irregularities, as above stated.

The problem-ofgetting the insoluble soap into the fiber may be solved intwo ways, but preferably is done in the beating engine, when the aper isin the aqueous pulp stage. It may a so be accomplished by treatment ofthe formed paper sheet, although this is more difiicult and willprobably require special apparatus in large commercial practice. Sinceeach fiber must be coated with the material, to fully waterproof a webof paper, the process involves the chemical formation of the insolublemetal salt in the presence of the fibers.

The preferred process is carried out by adding to the beater, haviugacharge of paper stock and water therein, a solubleof said metals.

acids employed in the first step, in su cient quantity to re-act withall of the soluble solve in the beater water so as to be insoaps, and,effect complete 'preci itation thereof, in the form of the insolub esoaps Thus in the specific process, of which the first step has beenstated, there is formed and added to the beater a solution of thesoluble salts of alumina, barium, lead, zinc,

or other metals of the insoluble organic soapgroup suflicient to effectcomplete precipitation, so that the total quantity of metallic soapsproduced will amount to from one to it is desired to produce.

three per cent of the weight of theboard that One salt which has shownsuperior results in the process is lead acetate, which can easily bebrought to solution in water, and 1s inexpensive.

The result of the precipitation of insoluble soap in the presence ofthe'fiber, is that the. individual fibers become coated with the same,and as the usual steps in the manu- 't'acture of paper are proceededwith, the resultlng sheet will have its fibers thoroughly coated, andwill exhibit the qualities above tion, and gain a thorough saturation ofeach fiber, it may be a vacuu'm.-

The saturated web is next treated with a solution of the metal salt, andagain is necessary to use pressureor thoroughly saturated, if necessarywith pressure or vacuum, so as to gain a complete reaction. resulting asbefore in the preclpltaiiou of the insoluble soaps;

Finally, if necessary, the sodium salts left by the reaction, may bewashed out of the web. by any desired method which will not disintegratethe web. and the web may then be calcndercd' and dried.

For weatherproof signs, to be exposed to the elements-over longperiodsof time, the board produced by my process is excellent,

' and the improved printing surface it affords,

insures longer life for the printed design upon it.

T1 '5 process 5 iould be distinguished from a sizing process, as itproceeds further than sizing, to the extent of the precipitation uponthe-fibers of an insoluble body in dispersed or colloidal form.

Having thus described the process, What is claimed as new and desired tobe secured by Letters Patent, is

The process of manufacturing weather resistant fiber board,whichconsists in thoroughly mixing fiber pulp in an aqueous solution ofsoap and treating the pulp with lead acetate to precipitate insolublelead soap in intimate admixture with said fiber, the quantity of soaprequired being sufficicnt to provide approximately not over three percent by Weight of insoluble soap on the basis of the pulp use-d.

DANESI M. HILTON. Executria: 0ftlze Estate of Robert W. Hilvton,Deceased.

